What's this noise from the rear wheel area?
 

1995 E320 Cabriolet at the right rear wheel makes a noise that changes pitch with the speed of the car, but doesn't change sound as you load or unload that side going around curves like a wheel bearing would do. Kind high, metallic sound. If you've ever had a car with wire wheel covers and the spokes were loose, it kinda sounds like that. Or sorta like a lug nut that fell off into the hubcap but not so loud. Took the wheel off and spun the axle by hand but couldn't duplicate the noise, just a little normal rumble or scrape from the pads. The dust shield isn't touching any moving parts either. Any other ideas? Could it still be a wheel bearing?

atikovi, pull the rear rotors and inspect the emergency brake mechanism for broken parts. (Be sure the emergency brake is not applied so you can remove the rear rotors.)

I checked that and nothing was loose, but the shoes were worn so I'll replace them and see what happens.

atikovi, if the emergency brake shoes were so badly worn that the lining was gone then metal-to-metal noise would be noticeable. Have the emergency brake shoes scored the rear rotors?

By worn I ment more like the edges were a bit ragged looking, not that the lining was gone.

Loose fitting center caps can make a noise like you describe. So can a slightly loose e-brake cable. If the cable is slightly loose it lets the clevis rattle about, especially over bumps.